铁离子-单宁酸处理增强牛颈静脉综合性能

经传统戊二醛(GA)交联的牛颈静脉易发生钙化,限制了其在临床上的广泛应用。在GA交联基础上增加单宁酸(TA)处理,取得了良好的抗钙化效果,但也存在组织柔顺性较差的不足。根据单宁酸易与金属阳离子产生螯合作用的特性,本研究尝试应用三价铁离子(Fe³⁺)与反应体系中的单宁酸形成螯合物,防止单宁酸过度反应,从而提高其抗钙化的综合性能。探索Fe³⁺添加方式和pH等反应条件,分别通过单轴拉伸实验测定力学性能、大鼠皮下植入实验测定钙化水平和两点弯曲法测定血管柔顺性,筛选出优化的TA-Fe³⁺处理方法,并对此方法处理得到的牛颈静脉进行生物相容性评价。结果表明,碱性条件(pH=8)下,TA处理前增加Fe³⁺处理步骤能改善TA固定牛颈静脉的组织柔顺性,柔顺度较TA组显著改善,同时保持了TA处理的力学强度;大鼠皮下植入21和60 d后钙含量显著低于GA组[21 d:(1.71±0.41) mg/g vs (38.12±7.40) mg/g; 60 d:(2.73±1.13) mg/g vs (124.19±14.22) ...     

单宁酸后处理牛颈静脉血管的血液相容性研究

评价经单宁酸后处理的牛颈静脉带瓣血管的血液相容性,探讨其在心血管外科中的应用前景。带瓣牛颈静脉经常规戊二醛处理后,再以单宁酸溶液进行后处理,然后进行体外动态凝血实验,血小板黏附性能实验,D-二聚体测定和补体激活实验进行血液相容性评价,与传统的戊二醛处理的带瓣牛颈静脉作平行对照。结果表明：（1）单宁酸处理后的带瓣牛颈静脉抗凝血性能优于对照组;（2）单宁酸处理后带瓣牛颈静脉血小板黏附比对照组明显减轻且变形小;（3）D-二聚体含量各组均在正常范围内,单宁酸处理前后无显著性差异（P〉0.05）;（4）补体激活实验中单宁酸处理后的带瓣牛颈静脉组补体C3a水平明显低于对照组（P〈0.05）。经单宁酸处理后带瓣牛静脉体外血液相容性得到改善,显示了在临床上应用的可能性。     

亲水性交联剂处理牛颈静脉的理化特征

分别用 4 %的 EX- 313与 0 .5 %的戊二醛处理牛颈静脉带瓣胶原管道 ,所获的材料分别进行外观、扫描电镜与光镜检查 ;另外进行大鼠皮下埋植试验 ,生物力学的测试 ,所获的数据进行 t检验。EX- 313处理后的材料比戊二醛处理者质地更接近天然血管 ,结构间充满空隙 ,抗张强度与戊二醛处理者相当 ,抗钙化方面 EX- 313处理者明显优于戊二醛处理者。用亲水性交联剂 EX- 313处理的生物材料在抗钙化与顺应性方面比戊二醛更有优势 ,由其处理的牛颈静脉有可能成为较理想心脏修复材料     

染料介导光氧化固定牛带瓣颈静脉的生物特性评价

为了解染料介导光氧化固定牛颈静脉的生物稳定性,抗钙化性和免疫原性,新鲜的牛颈带瓣静脉经染料介导光氧化法固定,分别进行化学消化和胃蛋白酶消化,上清液进行梯度聚丙烯酰胺电泳来了解其生物稳定性;将氧化固定的材料埋植于SD大鼠皮下,3周后取出,测钙含量、进行钙染色以及组织学检查了解其抗钙化性和免疫原性;采用戊二醛固定以及新鲜的牛带瓣颈静脉作为对照。染料介导光氧化固定的牛带瓣颈静脉经化学和酶消化之后的上清液电泳之后出现极淡的蛋白条带,明显淡于新鲜的未处理的材料,戊二醛固定的材料几乎不出现蛋白条带。皮下埋植3周后,钙含量测定,染料介导光氧化组显著低于戊二醛组,统计学上差异有显著性意义;钙染色,戊二醛组可见大量的钙沉积,新鲜组也可见钙沉积,但比戊二醛组少,染料介导光氧化组只见少量钙沉积;组织学检查提示光氧化组细胞浸润明显少于其他两组。体外动物实验提示,染料介导光氧化固定的牛带瓣颈静脉具有生物稳定性,低的钙化性和低免疫原性。     

新型抗钙化牛颈静脉管道材料的体外细胞毒性评价

背景：Triton X-100、环氧氯丙烷联合改性处理戊二醛固定的牛颈静脉管道是一种新型抗钙化右心管道材料,其生物相容性方面的研究较少。 目的：评价新型抗钙化牛颈静脉管道的体外细胞毒性。 方法：通过CCK-8法检测新型抗钙化牛颈静脉管道(实验组)及单纯戊二醛处理牛颈静脉管道材料浸提液(对照组)对L-929小鼠成纤维细胞的毒性作用,以第2,4天为检测时间点,计算细胞相对增殖率、对材料毒性进行分级。 结果与结论：CCK-8法细胞毒性试验显示新型抗钙化牛颈静脉管道材料浸提液第2,4天L-929细胞增殖率均在85%以上,毒性分级为1级,无细胞毒性,且显著优于对照组(P < 0.05)。提示经戊二醛、Triton X-100、环氧氯丙烷联合处理制备的新型抗钙化牛颈静脉管道材料无细胞毒性。     

牛颈静脉带瓣管道的研制及应用进展

随着心脏外科的发展,许多复杂先天性心脏病的手术中经常需要使用生物带瓣管道。牛颈静脉带瓣管道(bovinejugular vein conduit,BJVC)作为一种新型异种生物血管替代物,具有来源丰富,取材容易;长度、大小口径容易匹配,手术操作简单;血管及瓣膜生物力学性能适应人体右心系统低压环     

基于Cole-Cole模型评价纳米二氧化钛的细胞毒性作用

利用Cole-Cole模型评价不同剂量纳米二氧化钛(Nano-TiO₂)的细胞毒性作用,并探讨电生理机制。150和300 mg/L的Nano-TiO₂悬液作用人胃癌MGC803细胞24 h后,制备成细胞悬浮液。在1 kHz～100 MHz范围,采用Agilent 4294A精密阻抗分析仪测量了人胃癌MGC803细胞悬浮液电阻抗的幅值和相位角,经电阻抗频谱和Nyquist图的曲线拟合的残差分析,建立Cole-Cole模型参数,评估Nano-TiO₂对MGC803细胞导电性能的影响。结果表明,150和300 mg/L的Nano-TiO₂引起第一电阻抗增量(ΔZ₁)分别减少18.18%(P<0.001)和39.39%(P<0.001),第二电阻抗增量(ΔZ₂)分别减少6.56%(P<0.001)、8.2%(P<0.001),降低了MGC803细胞膜及其核膜的电阻,增加了其导电性能;第一特征频率(f_C1)分别增加19.74%(P<0.001)和29.67%(P<0.001),第二特征频率(f_C2)分别增加6.28%(P<0.001)、23.43%(P<0.001);第一散射角(β₁)分别降低1.35%(P>0.05)和2.70%(P<0.05)。Cole-Cole模型可评价Nano-TiO₂的细胞毒性作用并解释其电生理机制,为纳米颗粒的细胞毒理研究提供一种电特性方法。     

环氧交联牛心包材料内皮化的抗钙化作用研究

研究生物材料内皮化延缓钙化的效果 ,从材料学上改进生物瓣性能 ,提高其耐久性打下基础。方法 ,将环氧交联的牛心包材料体外内皮化后同时进行犬股动脉间位移植和腹部皮下包埋 ,与单纯戊二醛处理者和单纯环氧处理进行钙化程度对比。结果 :钙含量测试结果以内皮化环氧交联材料皮下包埋最低 ,未内皮化材料中以环氧处理者钙含量较低。结论 :环氧交联牛心包材料确可实现体外快速内皮化 ,生物材料的内皮化“活化”有赖于表面全部被自体存活内皮细胞覆盖才能实现 ,完全的内皮化确有抗钙化效果 ,两种动物模型研究生物材料抗钙化和内皮化时各有优缺点     

牛颈静脉带瓣管道的研制及应用进展

随着心脏外科的发展,许多复杂先天性心脏病的手术中经常需要使用生物带瓣管道.牛颈静脉带瓣管道(bovine jugular vein conduit,BJVC)作为一种新型异种生物血管替代物,具有来源丰富,取材容易;长度、大小口径容易匹配,手术操作简单;血管及瓣膜生物力学性能适应人体右心系统低压环境,可提供良好的血流动力学性能等优点[1-4].通过合适的处理方式,BJVC可广泛应用于心脏修复的补片材料、带瓣管道、大血管的修复材料及组织工程三维可降解带瓣支架等临床领域.     

酒精对戊二醛固定牛心包影响的实验研究

目的探讨酒精处理对戊二醛固定牛心包体内钙化和力学性能的影响。方法牛心包经戊二醛固定后,再用酒精处理,未经酒精处理组作为对照组。将两组牛心包埋植于大鼠皮下,分别于3周和2个月后取出,然后通过原子吸收光谱法和VonKossa钙染色评估两组牛心包钙含量变化。进行力学性能测试和热皱缩温度测定评估两组牛心包的物理性能。结果组织学检查显示酒精再处理对牛心包胶原纤维结构无明显破坏;大鼠皮下埋植实验显示酒精再处理能显著抑制戊二醛固定牛心包的钙化,3周时酒精再处理的戊二醛固定牛心包组钙含量是(1.08±0.30)mg/g,酒精未处理组钙含量是(24.55±7.16)mg/g;2个月时酒精再处理戊二醛固定牛心包组钙含量是(1.20±0.43)mg/g,酒精未处理组钙含量是(120.22±37.36)mg/g,差异有统计学意义;酒精再处理后牛心包的断裂伸长率增大,抗拉负荷增大,但抗拉强度改变无统计学意义;酒精再处理后牛心包的热皱缩温度下降。结论酒精处理戊二醛固定的牛心包动物体内实验显示有显著的抗钙化作用,并且具有良好的力学性能。     

Prophylaxis of osteoporosis with calcium, estrogens and/or eelcatonin: comparative longitudinal study of bone mass

Objective: To evaluate three different therapeutic regimens for the prevention of osteoporosis in natural and surgical postmenopausal women who had been found to have rapid bone loss in analytical studies. Methods: A total of 104 naturally or surgically postmenopausal women were studied, and subsequently followed-up during 1 year for avoidance of the influence of seasonal variation on bone mass, a factor overlooked in several studies. They were randomized into four groups of 26 patients each: the untreated control group (mean age 50 ± 5 years); the hormonal replacement treatment (HRT) group (mean age 48 ± 6 years), which was treated for 24 days each month with transdermal 17β-estradiol, 50 mg/day, together with medroxiprogesterone, 10 mg during 12 days; the calcium group (mean age 50 ± 4 years), which was treated with elemental calcium, 1 g/day; and the calcitonin group (mean age 50 ± 5 years), which was treated for 10 days each month with eel calcitonin, 40 IU/day and with elemental calcium, 500 mg/day. Full-body bone densitometry, for measuring total body bone mineral content (TBBMC), was carried out in all the women at baseline and 1 year. TBBMC was corrected for body weight by dividing its value by body weight (TBBMC/W). Results: After 1 year TBBMC/W was lower in every group: −2.14% (P < 0.001) in the control group; −0.14% (P = NS) in the HRT group (P < 0.05 vs. controls); −0.18% (P = NS) in the calcium group (P < 0.05 vs. controls); and −0.06% (P = NS) in the calcitonin group (P < 0.01 vs. controls; P < 0.05 vs. calcium and HRT). Conclusions: These findings show that all three treatments are effective in the prevention of postmenopausal loss of bone mass.     

Tannic acid mimicking dendrimers as small intestine submucosa stabilizing nanomordants

Chemical stabilization resulting in increased resistance to proteolytic degradation is one of the approaches in prevention of post-implantational aneurysm development in decellularized natural vascular scaffolds. Recently, tannic acid (TA) and tannic acid mimicking dendrimers (TAMD) have been suggested as potential stabilization agents for collagen and elastin. The aim of this work was to determine the stabilizing effects of TAMD on decellularized natural scaffolds. Vascular scaffolds fabricated from small intestine submucosa (SIS) and SIS plane sheets (Cook Biotech Inc.) were used. The biomechanical properties of the SIS vascular graft segments treated with TA and TAMD were tested. The effect of TAMD treatment on resistance to proteolytic degradation was evaluated by measuring biomechanical properties of TAMD stabilized and non-stabilized SIS specimens after incubation in collagenase solution. It was shown that treatment with TA as well as with TAMD increased the strength of tubular SIS as well as their resistance to proteolytic biodegradation manifested by preservation of biomechanical properties after collagenase treatment. Transmission electron microscopy demonstrated that treatment with TAMD increased the periodical pattern typical of collagen fiber ultrastructure as a result of the "mordant" effect. The possible collagen cross-linking effect of TAMD on SIS was investigated by differential scanning calorimetry (DSC). The treatment with TAMD induced a small, but detectable cross-linking effect, suggesting that TAMD do not establish extensive covalent cross links within the extracellular matrix but rather interact with collagen, thus rendering SIS scaffolds more resistant to proteolytic degradation.     

华蟾素对肝癌Bel-7402细胞放疗敏感性的影响及其作用机制的研究

目的 探讨华蟾素对肝癌Bel-7402细胞放疗敏感性的影响及其作用机制。方法 分别使用浓度为0.125、 0.250、 0.500、1.000 μg/mL华蟾素处理肝癌Bel-7402细胞24 h、48 h、72 h,噻唑蓝(MTT)法检测细胞增殖的影响,根据半数抑制浓度(IC₅₀)选择华蟾素浓度及作用时间。用0 μg/mL(对照组)和0.4 μg/mL华蟾素处理肝癌Bel-7402细胞,同时用剂量为0、2、4、6、8 Gy的6 MV X线进行照射,克隆形成实验检测细胞放疗敏感性。用IC₅₀为0.4 μg/mL华蟾素、6 Gy的X线分别单独或联合处理肝癌Bel-7402细胞,48 h后流式细胞仪检测细胞周期和细胞凋亡率;Western blot检测细胞中p50、p65、Bcl-2、cyclin D1蛋白表达情况。结果 华蟾素能够显著抑制肝癌Bel-7402细胞增殖,随着作用浓度的增加及作用时间的延长,细胞抑制率逐渐升高。华蟾素能够抑制经照射后的肝癌Bel-7402细胞克隆形成能力,细胞存活率显著低于对照组(P<0.05)。与对照组相比,华蟾素组、放疗组及联合组肝癌Bel-7402细胞G0/G1期细胞比例增多,S期细胞减少,细胞凋亡率升高,p50、p65、Bcl-2和cyclin D1蛋白表达降低,差异均有统计学意义(P值均＜0.05);联合组与华蟾素组和放疗组相比,细胞周期、细胞凋亡率及蛋白表达差异均有统计学意义(P值均<0.01)。结论 华蟾素能够增强肝癌Bel-7402细胞的放疗敏感性;其作用机制可能与华蟾素能够通过抑制核因子-κB信号通路及下调Bcl-2和cyclin D1蛋白表达,进而抑制细胞增殖、诱导细胞周期阻滞和细胞凋亡相关。     

高特质焦虑个体执行控制功能及其脑网络研究

利用行为学及复杂网络分析方法,探讨高特质焦虑(HTA)个体执行控制功能及其脑功能网络特点.以16名HTA个体为研究对象、16名低特质焦虑(LTA)个体为对照,进行Simon空间认知冲突任务,同步记录行为数据(反应时间及正确率)及64导脑电(EEG)信号.对EEG数据进行同步似然分析,选择合适阈值构建脑网络拓扑结构并计算...     

不同意识状态对音乐感知的差异性:基于音乐特征与脑电张量分解的研究

研究不同意识水平对音乐感知的差异性,探索不同意识水平与音乐感知之间的关系.被试共43名,其中7名正常意识被试、17名微意识状态(MCS)被试和19名植物状态(VS)被试.获取3种不同意识水平被试在聆听传统民乐《茉莉花》时的脑电,利用基于层次交替最小二乘法(HALS)非负张量分解,对被试在听音乐时产生的脑电提取张量成分,...     

Structural changes in pericardium tissue modified with tannic acid

INTRODUCTION: Structural modification of proteins, mainly collagen in connective tissues, is important in the manufacture of tissue-derived biomaterials. Natural compounds like genipin or tannic acid (TA) have been proposed instead of glutaraldehyde which shows cytotoxic effects on the processed tissue. Furthermore, calcification of glutaraldehyde-treated tissue limits the functional lifetime of bioprostheses. TA is known to form numerous hydrogen bonds with proteins. The purpose of our study was to investigate structural changes in porcine pericardium upon chemical modification with tannic acid. METHODS: Porcine pericardium tissue (PP) was soaked in 2% TA for 4, 24 or 48 hours. Changes in tissue structure were studied using electrophoresis (SDS-PAGE) and histological examination. Structural stability of PP tissue was evaluated by SDS/NaCl extraction method and enzymatic digestion with pancreatin. RESULTS: TA-modification of PP caused a time-dependent decrease in the number of peptides extracted from tissue. Microscopic studies revealed no significant morphological differences between native and TA-modified tissues, except for the native pancreatin-digested tissue where lack of both cells and low molecular peptides was observed. CONCLUSION: Modification of PP with TA causes the structural changes leading to an increase in the tissue resistance to SDS/NaCl extraction and enzymatic digestion, providing experimental evidence for the higher structural stability of TA-treated tissue.     

草鱼鱼皮胶原蛋白与NIH3T3成纤维细胞的相容性

体外检测草鱼鱼皮酸溶性胶原蛋白(FASC)的细胞相容性。采用MTT实验,检测不同浓度的FASC溶液或FASC涂层胶对NIH3T3成纤维细胞增殖能力的影响(n=6);利用transwell趋化实验,检测不同浓度的FASC溶液对成纤维细胞的趋化作用(n=3);利用transwell侵袭实验,检测不同浓度FASC涂层胶的细胞通透性(n=3)。结果表明,FASC溶液浓度依赖性地促进NIH3T3成纤维细胞增殖,16 μg/mL的FASC溶液在48和96 h的增殖率分别为63.7%±7.9%和87.3%±8.7%,较对照组有显著性差异(P<0.001)。NIH3T3细胞能够在FASC涂层胶上生长,各实验组与对照组相比,增殖率均无显著性差异(P > 0.05)。趋化实验显示,FASC溶液各浓度梯度组与阴性对照组的趋化指数均有显著性差异(P < 0.05),提示FASC对成纤维细胞具有趋化作用。侵袭实验结果显示,成纤维细胞可以通过FASC涂层胶。实验证实,FASC与NIH3T3细胞具有良好的相容性。     

Enhancement of bio-compatibility via specific interactions in polyesters modified with a bio-resourceful macromolecular ester containing polyphenol groups

Specific interactions and miscibility are demonstrated in a series of binary miscible blend comprising of bio-compatible/biodegradable polyesters, such as poly(epsilon-caprolactone) (PCL), poly(ethylene adipate) (PEA), or poly (butylene adipate) (PBA), and a macromolecular ester with polyphenol groups, tannic acid (TA). Thermal analysis and infrared spectroscopy were used for proving existence of favorable interactions, and polarized-light optical microscopy was used for characterizing the changes in crystal growth. The appearance of a single composition-dependent glass transition temperature (T(g)) observed by differential scanning calorimetry (DSC) indicated that TA is miscible with PCL, PBA, and PEA, respectively, over the entire range of compositions. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of specific intermolecular hydrogen bonding interactions between the carbonyl groups of polyesters and the phenolic hydroxyl groups of TA. The blend T(g)'s generally exhibited various extents of positive-then-negative deviation from linearity with the compositions. The T(g)-composition relationships for three blend systems could all be fitted by the Kwei equation with large negative q values of -80 to -110 for different polyesters. Significant effects by TA on the spherulitic crystallization growth in the polyester/TA blends were also discussed to support the miscibility and strong interactions. Overall, the behavior of blends of polyesters with TA is similar to that of blends of polyesters with poly(vinyl p-phenol) (PVPh) that have been more widely studied and reported. However, TA is naturally bio-resourceful, bio-compatible, and bio-degradable but PVPh is not. Synergism of miscibility, natural bio-compatibility, and biodegradability in these blends by introducing naturally biodegradable macromolecules such as TA may offer greater potential in intended applications.     

颈前路零切迹与钢板椎间融合系统治疗单节段脊髓型颈椎病疗效比较

目的 比较颈前路零切迹椎间融合系统(Zero-P)和颈前路钢板椎间融合系统(PCB)治疗单节段脊髓型颈椎病的疗效。方法 采用前瞻性随机对照试验方法对2012年8月—2014年10月63例前路手术治疗的单节段脊髓型颈椎病患者进行研究。63例患者按随机数字表法分为Zero-P组(32例)和PCB组(31例)分别行Zero-P和PCB治疗。观察两组手术时间、术中失血、椎间高度、颈椎Cobb角、JOA评分、颈椎功能障碍指数(NDI)和远期并发症,远期并发症包括螺钉位置丢失、吞咽困难和骨性融合不佳。结果 Zero-P组中1例因随访丢失予以剔除,最终每组均有31例研究对象。两组患者性别、年龄、手术节段、椎间高度、颈椎Cobb角、JOA评分、NDI评分差异均无统计学意义(P值均>0.05)。病例随访时间均大于12个月,Zero-P系统组随访时间(15.52±1.93)个月;PCB组随访(16.10±2.33)个月,差异无统计学意义(t=1.069,P>0.05)。Zero-P组、PCB组手术时间分别为(63.45±10.87)、(85.97±12.04)min,术中出血量分别为(44.35±11.53)、(66.26±19.62)mL,差异均有统计学意义(t=7.730、5.358,P值均<0.01)。两组患者手术后及末次随访时的恢复椎间高度、颈椎Cobb角较术前明显改善,差异均有统计学意义(P值均＜0.05);两组间在手术后和末次随访时,恢复椎间高度、颈椎Cobb角水平差异均无统计意义(P值均>0.05),但在末次随访时PCB组在术后维持Cobb角方面更有优势(P＜0.05)。末次随访时两组JOA评分、NDI评分均较术前明显改善(P值均＜0.05),Zero-P组的NDI评分改善程度优于PCB组(P＜0.01)。至末次随访,两组病例均获骨性融合,其中PCB组出现2例螺钉位置丢失、3例吞咽困难,远期并发症方面Zero-P组优于PCB组(P＜0.05)。结论 Zero-P和PCB在治疗单节段脊髓型颈椎病均可获得较满意的治疗效果。Zero-P组具有手术较简易、颈椎功能保留多、螺钉位置丢失和吞咽困难的相关的远期并发症发生率较低的优点。而较之Zero-P,PCB能够更好地维持颈椎术后生理曲度。